fix a lot of issues on psogc; add proxy module

- $ann implemented
- concurrency removed; server is now single-threaded, event-driven and much more stable
- rare seed is no longer the game id; ids are sequential from server startup so they weren't random at all before
- supports dropping privileges; now you can run it as root so it can open a sockets on low ports, then it will switch to the given user before serving any traffic
- newserv now behaves like a proxy if you run it with the --proxy-destination=<IP_OR_HOSTNAME> argument; there's also an (invisible) shell in this mode where you can inject commands to the server or client. e.g. it can always be christmas in the lobby if you do `sc DA 01 00 00`
- increased the mtu on PSODolphinConfig's tap0 configuration; this seems to make the connection more stable
- fixed some uninitialized memory bugs
- the shell is now event-driven and now uses libevent too; unfortunately this means readline doesn't work anymore (no history and vim-like shortcuts)
- made network command display consistent for input vs. output (the header appears in both cases now)
- fixed bugs in some subcommand handling (the BB logic was being applied to non-BB clients erroneously, causing most item drops not to work at all)
- fixed player tags in the short lobby data struct. unclear if this was actually a problem but it was inconsistent with other servers
- fixed "unused" field in game join command (actually it appears to be disable_udp and should be 1, not 0)
- cleaned up Server abstraction a bit
- rewrote some text functions; asan was complaining about the built-in ones for some reason
- added an optional welcome message

Client.hh

@@ -34,9 +34,7 @@ struct ClientConfigBB {
 };
 
 struct Client {
-  rw_lock lock;
-
-  // license & account 
+  // license & account
   std::shared_ptr<const License> license;
   char16_t name[0x20];
   ClientConfigBB config;
@@ -60,7 +58,6 @@ struct Client {
   uint64_t play_time_begin; // time of connection (used for incrementing play time on BB)
   uint64_t last_recv_time; // time of last data received
   uint64_t last_send_time; // time of last data sent
-  bool in_information_menu;
 
   // lobby/positioning 
   uint32_t area; // which area is the client in?